IRON Overview Information

Iron is a mineral. Most of the iron in the body is found in the hemoglobin of red blood cells and in the myoglobin of muscle cells. Iron is needed for transporting oxygen and carbon dioxide. It also has other important roles in the body.

People take iron supplements for preventing and treating low levels of iron (iron deficiency) and the resulting iron deficiency anemia. In people with iron deficiency anemia, the red blood cells can’t carry enough oxygen to the body because they don’t have enough iron. People with this condition often feel very tired.

Women sometimes take iron supplements to make up for iron lost in heavy menstrual periods. Iron-rich foods, such as pork, ham, chicken, fish, beans, and especially beef, liver, and lamb are also used.

How does it work?

Iron helps red blood cells deliver oxygen from the lungs to cells all over the body. Once the oxygen is delivered, iron then helps red blood cells carry carbon dioxide waste back to the lungs to be exhaled. Iron also plays a role in many important chemical reactions in the body.

IRON Uses & Effectiveness

Anemia caused by chronic disease. Many diseases such as cancer, kidney problems, or heart problems can cause anemia. Taking iron along with other medications such as epoetin alfa (erythropoietin, EPO, Epogen, Procrit) can help build red blood cells and reverse anemia in people with kidney problems or being treated for cancer with chemotherapy. Receiving iron intravenously (by IV) is more effective than taking supplements by mouth.

Iron deficiency. Taking iron supplements is effective for treating and preventing iron deficiency and anemia caused by too little iron in the body.

Coughs caused by ACE inhibitors. Medications used for high blood pressure called ACE inhibitors can sometimes cause coughing as a side effect. Some research shows that taking an iron supplement might reduce or prevent this side effect. The ACE inhibitor medications include captopril (Capoten), enalapril (Vasotec), lisinopril (Prinivil, Zestril), and many others.

Learning problems. Taking iron might help improve thinking, learning, and memory in children with low levels of iron.

Heart failure. Up to 20% of people who have heart failure also have low levels of iron in the body. Some research shows that giving iron intravenously can improve some symptoms of heart failure. It is not yet known if taking an iron supplement by mouth would help.

Iron deficiency during pregnancy. Taking iron might reduce the risk of anemia caused by too little iron in the body when taken by women who are pregnant.

Breath-holding attacks. Early research suggests that taking iron by mouth or through a shot reduces the frequency of breath-holding attacks in children.

Child development. Early research shows that iron does not improve mental performance in infants and children who do not have anemia. However, there might be an improvement in the development of motor skills such as coordination.

Fatigue. There is some early evidence that iron supplements might improve unexplained fatigue in non-anemic women.

Child growth. Early evidence suggests that taking iron supplements alone by mouth does not increase growth in children.

Physical performance. Early research suggests that taking iron supplements or eating foods enriched with iron daily for 1-2 months decreases the heart rates of running children.

Canker sores.

A digestive tract disease called Crohn's disease.

Depression.

Female infertility.

Heavy menstrual bleeding.

Restless leg syndrome.

Other conditions.

More evidence is needed to rate iron for these uses.

IRON Side Effects & Safety

Iron is LIKELY SAFE for most people when it is taken by mouth in appropriate amounts. However, it can cause side effects including stomach upset and pain, constipation or diarrhea, nausea, and vomiting. Taking iron supplements with food seems to reduce some of these side effects. However, food can also reduce how well the body absorbed iron. Iron should be taken on an empty stomach if possible. If it causes too many side effects, it can be taken with food. Try to avoid taking it with foods containing dairy products, coffee, tea, or cereals.

There are many forms of iron products such as ferrous sulfate, ferrous gluconate, ferrous fumarate, and others. Some products, such as those containing polysaccharide-iron complex (Niferex-150, etc), claim to cause fewer side effects than others. But there is no reliable evidence to support this claim.

Some enteric coated or controlled release iron products might reduce nausea for some people; however, these products also have less absorption by the body.

Liquid iron supplements may blacken teeth.

High doses of iron are LIKELY UNSAFE, especially for children. Iron is the most common cause of poisoning deaths in children. Doses as low as 60 mg/kg can be fatal. Iron poisoning can cause many serious problems including stomach and intestinal distress, liver failure, dangerously low blood pressure, and death. If you suspect an adult or child has taken more than the recommended amount of iron, call your healthcare professional or the nearest poison control center immediately.

There is some concern that high intake of iron might increase the chance of developing heart disease. Some studies show that people with high intake of iron, especially from food sources such as red meat, are more likely to have heart disease. This may be especially true for people with type 2 diabetes. But this is controversial. Other studies do not show that iron increases the chance of heart disease. It is too soon to tell for sure if iron increases the chance of heart disease.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Iron is LIKELY SAFE for pregnant and breast-feeding women who have enough iron stored in their bodies when used in doses below the tolerable upper intake level (UL) of 45 mg per day of elemental iron. The UL is the highest level of intake at which no harmful side effects are expected. However, iron is LIKELY UNSAFE when taken by mouth in high doses. If you do not have iron deficiency, do not take more than 45 mg per day of elemental iron per day. Higher doses frequently cause stomach and intestinal side effects such as nausea and vomiting. High levels of hemoglobin at the time of delivery are associated with bad pregnancy outcomes. Hemoglobin is the molecule in red blood cells that contains iron.

Diabetes: There is concern that a diet that is high in iron might increase the risk of heart disease in women with type 2 diabetes, although this has not been proven. If you have diabetes, discuss your iron intake with your healthcare provider.

Stomach or intestinal ulcers: Iron might cause irritation and make these conditions worse. Use iron with care.

Intestinal inflammation, such as ulcerative colitis or Crohn’s disease: Iron might cause irritation and make these conditions worse. Use iron with care.

Hemoglobin disease, such as thalassemia: Taking iron might cause iron overload in people with these conditions. If you have a hemoglobin disease, don’t take iron unless directed to do so by your healthcare provider.

Premature infants: Giving iron to premature infants with low blood levels of vitamin E can cause serious problems. The vitamin E deficiency should be corrected before giving iron. Talk with your healthcare provider before giving iron to a premature infant.

IRON Interactions

Iron might decrease how much antibiotic the body absorbs. Taking iron along with some antibiotics might decrease the effectiveness of some antibiotics. To avoid this interaction take iron two hours before or two hours after taking antibiotics.

Iron can attach to tetracycline antibiotics in the stomach and decrease how much tetracycline antibiotics the body can absorb. Taking iron along with tetracycline antibiotics might decrease the effectiveness of tetracycline antibiotics. To avoid this interaction take iron two hours before or four hours after taking tetracyclines.

Iron can decrease how much bisphosphate the body absorbs. Taking iron along with bisphosphates can decrease the effectiveness of bisphosphates. To avoid this interaction take bisphosphonate at least two hours before iron or later in the day.

Iron can decrease how much methyldopa (Aldomet) the body absorbs. Taking iron along with methyldopa (Aldomet) might decrease the effectiveness of methyldopa (Aldomet). To prevent this interaction take iron at least two hours before or after taking methyldopa (Aldomet).

Mycophenolate Mofetil (CellCept) interacts with IRON

Iron might decrease how much mycophenolate mofetil (CellCept) the body absorbs. Taking iron along with mycophenolate mofetil (CellCept) might decrease the effectiveness of mycophenolate mofetil (CellCept). To avoid this interaction take iron at least two hours after mycophenolate mofetil (CellCept).

Penicillamine (Cuprimine, Depen) interacts with IRON

Penicillamine is used for Wilson's disease and rheumatoid arthritis. Iron might decrease how much penicillamine your body absorbs and decrease the effectiveness of penicillamine. To avoid this interaction take iron two hours before or two hours after taking penicillamine.

Iron is important for producing new blood cells. Chloramphenicol might decrease new blood cells. Taking chloramphenicol for a long time might decrease the effects of iron on new blood cells. But most people only take chloramphenicol for a short time so this interaction isn't a big problem.

IRON Dosing

The following doses have been studied in scientific research:

BY MOUTH:

Iron-deficiency in adults: 50-100 mg elemental iron three times daily. Doses between 30-120 mg weekly have been used in adult women. For treating children with iron deficiency anemia: the dose is 4-6 mg/kg per day divided into three doses. For both adults and children, 2-3 months of treatment can reverse anemia but might not rebuild the body’s supply of stored iron. Therefore, treatment is usually continued another 6 months to build up the body’s iron reserves.

For preventing iron deficiency in children, the American Academy of Pediatrics recommends iron supplements for some groups. For breast-fed infants, elemental iron 1 mg/kg/day is recommended from ages 4-6 months. Infants from 6-12 months should get 11 mg/day from food or supplements. For pre-term infants, 2 mg/kg/day for the first year is recommended. This should be continued until the baby is switched to formula or otherwise getting enough iron from food sources. Formula-fed children get enough iron from infant formula. Toddlers aged 1-3 years usually get enough iron from foods to meet the recommended daily amount of 7 mg/day; however, a supplement can be added if needed.

The adequate intake (AI) of iron for infants 6 months of age and less is 0.27 mg/day. For older infants and children, the recommended daily allowances (RDAs) for iron are: Infants 7 to 12 months, 11 mg/day; children 1 to 3 years, 7 mg/day; 4 to 8 years, 10 mg/day; 9 to 13 years, 8 mg/day; boys 14 to 18 years, 11 mg/day; girls 14 to 18 years, 15 mg/day. For adults, the RDA for iron is 8 mg/day for men ages 19 and older, and women ages 51 and older. For women 19 to 50 years, the RDA is 18 mg/day. For pregnant women, the RDA is 27 mg/day. For breast-feeding women, the RDA is 10 mg/day for ages 14 to 18 years, and 9 mg/day for ages 19 to 50.

Tolerable Upper Intake Levels (UL), the highest intake at which no unwanted side effects are expected, for iron are: infants and children birth to age 13, 40 mg/day; people age 14 and older (including pregnancy and breastfeeding), 45 mg/day. UL recommendations do not apply to people under medical supervision for iron deficiency.

There are many forms of iron supplements which contain different amounts of elemental iron: 1 gram of ferrous gluconate = 120 mg elemental iron (12% iron); 1 gram of ferrous sulfate = 200 mg elemental iron (20% iron); 1 gram of ferrous fumarate = 330 mg elemental iron (33% iron). The effectiveness and side effects are similar for these different forms when used in equal doses of elemental iron.

Allen, L. H., Peerson, J. M., and Olney, D. K. Provision of multiple rather than two or fewer micronutrients more effectively improves growth and other outcomes in micronutrient-deficient children and adults. J Nutr 2009;139(5):1022-1030. View abstract.

Driva, A., Kafatos, A., and Salman, M. Iron deficiency and the cognitive and psychomotor development of children: a pilot study with institutionalised children. Early Child Development and Care 1985;22:73-82.

Geerligs, P. P., Brabin, B., Mkumbwa, A., Broadhead, R., and Cuevas, L. E. The effect on haemoglobin of the use of iron cooking pots in rural Malawian households in an area with high malaria prevalence: a randomized trial. Trop.Med.Int.Health 2003;8(4):310-315. View abstract.

Zegrean, M. Association of body iron stores with development of cardiovascular disease in the adult population: a systematic review of the literature. Can J Cardiovasc.Nurs. 2009;19(1):26-32. View abstract.

Zhou, S. J., Gibson, R. A., and Makrides, M. Routine iron supplementation in pregnancy has no effect on iron status of children at six months and four years of age. J Pediatr 2007;151(4):438-440. View abstract.

Baker RD, Greer FR; Committee on Nutrition. Diagnosis and prevention of iron deficiency and iron-deficiency anemia in infants and young children (0-3 years of age). Pediatrics 2010;126:1040-50. View abstract.

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